1. Field of the Invention
The present invention relates to a ratchet wrench, and more particularly to a ratchet wrench having an exact limit effect.
2. Description of the Related Art
In general, a conventional ratchet wrench comprises a handle, a drive head mounted on a distal end of the handle and having a first end formed with a receiving hole, a mediate portion formed with a receiving recess communicating with the receiving hole, and a second end formed with a receiving chamber communicating with the receiving recess, a ratchet wheel mounted in the receiving hole of the drive head, a pawl member pivotally mounted in the receiving recess of the drive head and engaged with the ratchet wheel, and a control knob rotatably mounted in the receiving chamber of the drive head and rested on the pawl member to push the pawl member to press the ratchet wheel to control the drive direction of the ratchet wheel. Thus, by control of the control knob, the ratchet wheel is rotated in one direction only when the drive head is rotated.
However, the control knob is not easily positioned in the receiving chamber of the drive head rigidly and stably, thereby causing inconvenience to a user when operating the control knob. In addition, the conventional ratchet wrench has a complicated construction, thereby greatly increasing the costs of fabrication.